The oil is supplied to the “P” port and pases through the check valve CV1, CV2 and pilot operated check valve POV (option) to the high‐pressure side. At the same time, the “T” port is connected to the tank.
Now the entire flow of the pump will pass straight through the intensifier, and a cylinder on the high‐pressure side “H” will move rapidly forwards.
When the pressure rises on the high‐pressure side, CV2 and POV close, and the oil will now fill Vol.1.
In Fig.1 Vol.2 is connected to PCV, which is connected to the tank. The pressure build‐up in Vol.1 causes the piston HP and LP move left.
When the high‐pressure piston HP passes pilot string 1, the latter is pressurised, and PCV changes position. This occurs because the right area of PCV is greater than the left of it, where pilot string 2 is constantly pressurised.
Vol.2 is thus connected to the pump, and the piston LP and HP move right as the area LP is depressurised, and PCV returns to its original position.
This continues until the pressure on the high‐pressure side has increased by a factor equivalent to the ration between the areas of LP and HP. If the pressure on the high‐pressure side falls, a new cycle starts automatically.
Pressure can be relieved from the high‐pressure side by leading the pump flow into the “T” port and connecting the “P” port to the tank. Pilot string 3 is thus pressurised and POV opens. The oil from the high‐pressure side is now led directly back to the tank through POV and the “P” port.